Pacific Premier Bancorp (PPBI) S-4Registration of securities issued in business combination transactions

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OPUS BANK ANNUAL REPORT ON FORM 10-K FOR THE FISCAL YEAR ENDED DECEMBER 31, 2019 TABLE OF CONTENTS
PART IV

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As filed with the Securities and Exchange Commission on March 13, 2020

Registration No. 333-                

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

PACIFIC PREMIER BANCORP, INC.
(Exact name of Registrant as specified in its charter)

17901 Von Karman Ave., Suite 1200
Irvine, California 92614
(949) 864-8000
(Address, including zip code and telephone number, including
area code, of Registrant's principal executive offices)

Steven R. Gardner
President and Chief Executive Officer
Pacific Premier Bancorp, Inc.
17901 Von Karman Ave., Suite 1200
Irvine, California 92614
(949) 864-8000
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale to the public:
As soon as practicable following the effectiveness of this Registration Statement, satisfaction or waiver of the other conditions to closing of the merger described herein, and consummation of the merger.

             If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.    o

             If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

             If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

             Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

             If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. o

             If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

             Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) o

             Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) o

Calculation of Registration Fee

(1)

Based upon an estimate of the maximum number of shares of common stock, par value $0.01 per share, of Pacific Premier Bancorp, Inc., or Pacific Premier, to be issued pursuant to the Agreement and Plan of Reorganization, dated as of January 31, 2020, or the merger agreement, by and among Pacific Premier, Pacific Premier Bank and Opus Bank, or Opus, based on 36,374,918 shares of Opus common stock, no par value per share, or Opus common stock, that may be outstanding at the effective time of the merger of Opus with and into Pacific Premier Bank, with Pacific Premier Bank as the surviving institution, which we refer to as the merger. The number of outstanding shares of Opus common stock includes (a) 677,002 restricted shares of Opus common stock that may vest in connection with the merger, (b) 1,555,550 shares of Opus common stock that may be issued to the holders of Opus series A non-cumulative, non-voting preferred stock, no par value per share, or Opus preferred stock, (c) 311,350 shares of Opus common stock that may be issued to the holders of Opus preferred stock upon the exercise of all outstanding warrants to purchase Opus preferred stock, (d) 140,625 shares of Opus common stock that may be issued upon exercise of all outstanding warrants to purchase shares of Opus common stock, (e) 677,002 shares of Opus common stock that may be issued upon exercise or vesting of outstanding awards made pursuant to Opus's 2010 Long-Term Incentive Plan, as amended and its 2018 Long-Term Incentive Plan, and (f) an exchange ratio 0.9000 of a share of Pacific Premier common stock for each share of Opus common stock being converted into, and canceled in exchange for the right to receive shares of Pacific Premier common stock. Pursuant to Rule 416 under the Securities Act of 1933, as amended, or the Securities Act, this Registration Statement also covers additional securities that may be issued as a result of stock splits, stock dividends or similar transactions.

(2)

Pursuant to Rule 457(f) under the Securities Act, and solely for the purpose of calculating the registration fee, the proposed maximum aggregate offering price is based on $17.535, which is the average high and low prices reported for Opus's common stock on the NASDAQ Global Select Market on March 11, 2020, which was within five business days prior to the date of filing of this Registration Statement, in accordance with Rule 457(f)(1).

(3)

Determined in accordance with Section 6(b) of the Securities Act at a rate of $129.80 per $1,000,000 of the proposed maximum aggregate offering price.

             The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant will file a further amendment which specifically states that this Registration Statement will thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement will become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

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THE INFORMATION IN THIS JOINT PROXY STATEMENT/PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. PACIFIC PREMIER BANCORP, INC. MAY NOT ISSUE THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS JOINT PROXY STATEMENT/PROSPECTUS IS NOT AN OFFER TO SELL THESE SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY THESE SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

PRELIMINARY JOINT PROXY STATEMENT/PROSPECTUS
SUBJECT TO COMPLETION, DATED MARCH 13, 2020

17901 Von Karman Avenue, Suite 1200
Irvine, California 92614

To the shareholders of Pacific Premier Bancorp, Inc.:

          On January 31, 2020, Pacific Premier Bancorp, Inc., which we refer to as Pacific Premier, Pacific Premier Bank, the wholly-owned bank subsidiary of Pacific Premier, and Opus Bank, which we refer to as Opus, entered into an agreement and plan of reorganization, which we refer to as the merger agreement, to acquire Opus. If the required shareholder and regulatory approvals are obtained, all closing conditions are satisfied or waived and the merger is subsequently completed, Opus will be merged with and into Pacific Premier Bank, with Pacific Premier Bank as the surviving institution, which we refer to as the merger.

          You are cordially invited to attend a special meeting of Pacific Premier's shareholders, referred to as the Pacific Premier special meeting, to be held at             a.m., Pacific Time, on                at 17901 Von Karman Avenue, Suite 200, Irvine, California 92614. At the Pacific Premier special meeting, Pacific Premier's shareholders will be asked to consider and vote upon a proposal to approve the issuance of shares of Pacific Premier common stock, par value $0.01 per share, which we refer to as Pacific Premier common stock, in connection with the merger. Opus also will hold a special meeting of its shareholders to consider the proposed merger agreement and related matters. Pacific Premier, Pacific Premier Bank and Opus cannot complete the proposed merger unless Pacific Premier's shareholders vote to approve the issuance of shares of Pacific Premier common stock in connection with the merger and Opus's shareholders vote to approve the merger agreement. This letter is accompanied by the attached joint proxy statement/prospectus, which Pacific Premier's board of directors is providing to solicit your proxy to vote for the approval of the issuance of shares of Pacific Premier common stock in connection with the merger. We refer to this solicitation as the Pacific Premier proxy solicitation.

          If the required shareholder and regulatory approvals are obtained and the merger is subsequently completed, upon effectiveness of the merger,

•

each outstanding share of Opus common stock, no par value, which we refer to as Opus common stock, will be converted into, and canceled in exchange for, the right to receive 0.9000 of a share of Pacific Premier common stock, which we refer to as the exchange ratio; and



•

each outstanding share of Opus series A non-cumulative, non-voting preferred stock, or Opus preferred stock, will be converted into, and canceled in exchange for, the right to receive that number of shares of Pacific Premier common stock equal to the product of (i) the number of shares of Opus common stock into which such share of Opus preferred stock is convertible in connection with, and as a result of, the merger, and (ii) the exchange ratio.

Cash will be paid in lieu of any fractional share interest. We refer to the aggregate consideration to be paid to the Opus shareholders in the merger as the merger consideration.

          The implied value of the merger consideration to be paid to Opus shareholders is based on the exchange ratio of 0.9000 of a share of Pacific Premier common stock for each share of Opus common stock. The implied value per share of Opus common stock on            , 2020, was $          , which amount was based on the $        closing price per share of Pacific Premier common stock on that date. The value of the merger consideration will fluctuate based on the market price of Pacific Premier common stock. Consequently, the value of the merger consideration will not be known at the time you vote on the issuance of shares of Pacific Premier common stock in connection with the merger. Pacific Premier expects to issue approximately            shares of Pacific Premier common stock in the aggregate upon completion of the merger.Pacific Premier's common stock is listed on the NASDAQ Global Select Market under the symbol "PPBI." You should obtain current market quotations for the Pacific Premier common stock.

          Based on our reasons for the merger described in the accompanying document, our board of directors has determined that the issuance of shares of Pacific Premier common stock in connection with the merger is in the best interests of Pacific Premier and its shareholders.Accordingly, our board of directors unanimously recommends that you vote "FOR" the issuance of shares of Pacific Premier common stock in connection with the merger. The accompanying joint proxy statement/prospectus gives you detailed information about the Pacific Premier special meeting, the merger and the issuance of shares of Pacific Premier common stock in connection with the merger and related matters. In addition to being a proxy statement of Pacific Premier, this document is also the proxy statement for the solicitation of proxies from Opus shareholders to vote to approve the merger agreement and is the prospectus of Pacific Premier for the shares of its common stock that will be issued to Opus shareholders in connection with the merger.

          We encourage you to read this entire document carefully, including the considerations discussed under "Risk Factors" beginning on page 41, and the appendices to the accompanying joint proxy statement/prospectus, which include the merger agreement.

          Your vote is very important. The merger cannot be completed unless a majority of the votes cast by the holders of shares of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting vote in favor of the approval of the issuance of shares of Pacific Premier common stock in connection with the merger. Whether or not you plan to attend the Pacific Premier special meeting, please take the time to vote by completing and mailing the enclosed proxy card or by following the instructions to vote via the Internet or by telephone indicated on the proxy card.

          We appreciate your continuing loyalty and support and, should you choose to attend, we look forward to seeing you at the Pacific Premier special meeting.

		Sincerely,
		Steven R. Gardner Chairman, President and Chief Executive Officer

          Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the shares of Pacific Premier common stock to be issued in the merger or determined if this joint proxy statement/prospectus is accurate or adequate. Any representation to the contrary is a criminal offense.

          The securities to be issued in connection with the merger are not savings accounts, deposits or other obligations of any bank or savings association and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

          This joint proxy statement/prospectus is dated            , 2020 and is being first mailed to Pacific Premier shareholders and Opus on or about            , 2020.

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19900 MacArthur Boulevard, 12^th Floor
Irvine, California 92612

To the shareholders of Opus Bank:

        On January 31, 2020, Pacific Premier Bancorp, Inc., which we refer to as Pacific Premier, Pacific Premier Bank, the wholly-owned bank subsidiary of Pacific Premier, and Opus Bank, which we refer to as Opus, entered into an agreement and plan of reorganization, which we refer to as the merger agreement, to acquire Opus Bank, which we refer to as Opus. If the required shareholder and regulatory approvals are obtained, all closing conditions are satisfied or waived and the merger is subsequently completed, Opus will be merged with and into Pacific Premier Bank, with Pacific Premier Bank as the surviving institution, which we refer to as the merger.

        You are cordially invited to attend a special meeting of Opus's shareholders, referred to as the Opus special meeting, to be held at 9:00 a.m., Pacific Time, on                at the Pacific Club, 4110 MacArthur Blvd, Newport Beach, California 92660. At the Opus special meeting, Opus's shareholders will be asked to consider and vote upon a proposal to approve the proposed merger agreement, a proposal to approve on a non-binding, advisory basis the compensation that certain named executive officers of Opus may receive that is based on or otherwise relates to the merger and related matters. Pacific Premier will also hold a special meeting of shareholders to consider the issuance of shares of Pacific Premier common stock, par value $0.01 per share, which we refer to as Pacific Premier common stock, in connection with the merger. Pacific Premier, Pacific Premier Bank and Opus cannot complete the proposed merger unless Pacific Premier's shareholders vote to approve the issuance of shares of Pacific Premier common stock in connection with the merger and Opus's shareholders vote to approve the merger agreement. This letter is accompanied by the attached joint proxy statement/prospectus, which Opus's board of directors, or the Opus board, is providing to you to solicit your vote for the approval of the merger agreement. We refer to this solicitation as the Opus proxy solicitation.

        If the required shareholder and regulatory approvals are obtained and the merger is subsequently completed, upon effectiveness of the merger,

•

each outstanding share of Opus common stock, no par value, which we refer to as Opus common stock, will be converted into, and canceled in exchange for, the right to receive 0.9000 of a share of Pacific Premier common stock, which we refer to as the exchange ratio; and



•

each outstanding share of Opus series A non-cumulative, non-voting preferred stock, no par value, which we refer to as Opus preferred stock, will be converted into, and canceled in exchange for, the right to receive that number of shares of Pacific Premier common stock equal to the product of (i) the number of shares of Opus common stock into which such share of Opus preferred stock is convertible in connection with, and as a result of, the merger, and (ii) the exchange ratio.

Cash will be paid in lieu of any fractional share interest. We refer to the aggregate consideration to be paid to Opus shareholders in the merger as the merger consideration.

        The implied value of the merger consideration to be paid to Opus shareholders is based on the exchange ratio of 0.9000 of a share of Pacific Premier common stock for each share of Opus common stock. The implied value per share of Opus common stock on                , 2020, was $        , which amount was based on the $        closing price per share of Pacific Premier common stock on that date. The value of the merger consideration will fluctuate based on the market price of Pacific Premier common stock. Consequently, the value of the merger consideration will not be known at the time you vote on the merger agreement. Based on the current number of shares of Opus common stock and Opus preferred stock outstanding, Pacific Premier expects to issue approximately             shares of Pacific Premier common stock in the aggregate upon completion of the merger.Pacific Premier's

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common stock is listed on the NASDAQ Global Select Market under the symbol "PPBI." You should obtain current market quotations for the Pacific Premier common stock. Opus's common stock is traded on the NASDAQ Global Select Market under the symbol "OPB." You should obtain current market quotations for the Opus common stock.

        Based on the reasons for the merger described in the accompanying document, our board of directors has determined that the merger, the merger agreement and the transactions contemplated by the merger agreement are in the best interests of Opus and its shareholders.Accordingly, our board of directors has unanimously recommended that you vote "FOR" the proposal to approve the merger agreement (including the Agreement of Merger incorporated therein) and the merger and "FOR" each of the other proposals described in the accompanying joint proxy statement/prospectus. The accompanying joint proxy statement/prospectus describes the Opus special meeting, the merger agreement and related matters. In addition to being a proxy statement of Opus, this document also is the proxy statement for the solicitation of proxies from Pacific Premier shareholders to vote to approve the issuance of shares of Pacific Premier common stock in connection with the merger and is the prospectus of Pacific Premier for the shares of its common stock that will be issued to the Opus shareholders in connection with the merger.

        We encourage you to read this entire document carefully, including the considerations discussed under "Risk Factors" beginning on page 41, and the appendices to the accompanying joint proxy statement/prospectus, which include the merger agreement.

        Holders of Opus preferred stock will be entitled to dissenters' rights in connection with the merger. A summary of the dissenters' rights that may be available to those holders is described in the section entitled "The Merger—Dissenters' Rights for Holders of Opus Preferred Stock" beginning on page of the enclosed joint proxy statement/prospectus. Please note that if Opus preferred shareholders wish to exercise dissenters' rights, they must not sign or return a proxy approving the proposal to approve the merger agreement (including the Agreement of Merger incorporated therein) and the merger. However, it is not necessary to affirmatively vote against or disapprove the proposal to approve the merger agreement (including the Agreement of Merger incorporated therein) and the merger in order to preserve your dissenters' rights. In addition, holders of Opus preferred stock must take all other steps necessary to perfect their dissenters' rights.

        Your vote is very important. The merger cannot be completed unless the holders of a majority of the outstanding shares of Opus common stock and a majority of the outstanding shares of Opus preferred stock, voting as separate classes, entitled to vote at the Opus special meeting vote in favor of the proposal to approve the merger agreement (including the Agreement of Merger incorporated therein) and the merger. Whether or not you plan to attend the Opus special meeting, please take the time to vote by completing and mailing the enclosed proxy card or by following the instructions to vote via the Internet or by telephone indicated on the proxy card.

        We appreciate your continuing loyalty and support and, should you choose to attend, we look forward to seeing you at the Opus special meeting.

		Sincerely,
		Paul W. Taylor President and Chief Executive Officer

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the shares of Pacific Premier common stock to be issued in the merger or

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determined if this joint proxy statement/prospectus is accurate or adequate. Any representation to the contrary is a criminal offense.

        The securities to be issued in connection with the merger are not savings accounts, deposits or other obligations of any bank or savings association and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

        This joint proxy statement/prospectus is dated                , 2020 and is being first mailed to Opus shareholders and Pacific Premier shareholders on or about                , 2020.

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PACIFIC PREMIER BANCORP, INC.
17901 Von Karman Avenue, Suite 1200
Irvine, California 92614

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS
To Be Held on                        , 2020

To the shareholders of Pacific Premier Bancorp, Inc.:

        We will hold a special meeting of shareholders of Pacific Premier Bancorp, Inc., or Pacific Premier, at             a.m., Pacific Time, on                    at 17901 Von Karman Avenue, Suite 200, Irvine, California 92614, for the following purposes:

1.

Approval of the Issuance of Shares of Pacific Premier Common Stock.    To consider and vote upon a proposal to approve the issuance of shares of Pacific Premier common stock to the shareholders of Opus Bank pursuant to an Agreement and Plan of Reorganization, dated as of January 31, 2020, by and among Pacific Premier, Pacific Premier Bank and Opus Bank, referred to in this notice as the merger agreement, pursuant to which Opus Bank will merge with and into Pacific Premier Bank, with Pacific Premier Bank as the surviving institution, which transaction is referred in this notice as the merger. We refer to such proposal as the share issuance proposal. A copy of the merger agreement is attached as Appendix A to the accompanying joint proxy statement/prospectus of which this notice is a part; and



2.

Adjournment.    To consider and vote upon a proposal to adjourn the Pacific Premier special meeting to a later date or dates, if necessary, to permit further solicitation of proxies if there are not sufficient votes at the time of the Pacific Premier special meeting to approve the issuance of shares of Pacific Premier common stock in connection with the merger. We refer to such proposal as the Pacific Premier adjournment proposal.

        No other business may be conducted at the Pacific Premier special meeting.

        We have fixed the close of business on                    , 2020 as the record date for the determination of shareholders entitled to notice of and to vote at the Pacific Premier special meeting. Only holders of Pacific Premier common stock of record at the close of business on that date will be entitled to notice of and to vote at the Pacific Premier special meeting or any adjournment or postponement of the special meeting.

        The Pacific Premier board of directors has unanimously approved the merger agreement and the transactions contemplated therein and has determined that the merger is in the best interests of Pacific Premier and its shareholders, and unanimously recommends that shareholders vote "FOR" approval of the share issuance proposal and "FOR" approval of the Pacific Premier adjournment proposal.

        If you have any questions concerning the merger or would like additional copies of the joint proxy statement/prospectus or need help voting your shares of Pacific Premier common stock, please contact Steven R. Gardner, Pacific Premier's Chairman, President and Chief Executive Officer, at (949) 864-8000, or Ronald J. Nicolas, Jr., Pacific Premier's Senior Executive Vice President and Chief Financial Officer, at (949) 864-8000.

        Your vote is very important.    Whether or not you plan to attend the Pacific Premier special meeting, please promptly complete, sign, date and return your proxy card in the enclosed envelope or vote via the Internet or by telephone pursuant to the instructions provided on the enclosed proxy card.

		By Order of the Board of Directors
		Steven R. Gardner Chairman, President and Chief Executive Officer

Irvine, California                    , 2020

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OPUS BANK
19900 MacArthur Boulevard, 12^th Floor
Irvine, California 92612

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS
To Be Held on                    , 2020

To the shareholders of Opus Bank:

        We will hold a special meeting of shareholders of Opus Bank, or Opus, at 9:00 a.m., Pacific Time, on                at the Pacific Club, 4110 MacArthur Blvd, Newport Beach, California 92660, for the following purposes:

1.

Approval of the Merger Agreement and Merger.    To consider and vote upon a proposal to approve the Agreement and Plan of Reorganization, dated as of January 31, 2020, by and among Pacific Premier Bancorp Inc., Pacific Premier Bank and Opus (including the Agreement of Merger incorporated therein), referred to in this notice as the merger agreement, pursuant to which Opus will merge with and into Pacific Premier Bank, with Pacific Premier Bank as the surviving institution, which transaction is referred in this notice as the merger, and the merger. We refer to such proposal as the merger proposal. A copy of the merger agreement is attached as Appendix A to the accompanying joint proxy statement/prospectus of which this notice is a part;



2.

Merger-Related Compensation.    To consider and vote, on a non-binding, advisory basis, upon a proposal to approve of the compensation that certain named executive officers of Opus may receive that is based on or otherwise relates to the merger. We refer to such proposal as the compensation proposal; and



3.

Adjournment.    To consider and vote upon a proposal to adjourn the Opus special meeting to a later date or dates, if necessary, to permit further solicitation of proxies if there are not sufficient votes at the time of the Opus special meeting to approve the merger proposal. We refer to such proposal as the Opus adjournment proposal.

        No other business may be conducted at the Opus special meeting.

        We have fixed the close of business on                        , 2020 as the record date for the determination of shareholders entitled to notice of and to vote at the Opus special meeting. Only holders of record of Opus common stock and holders of record of Opus preferred stock at the close of business on that date will be entitled to notice of and to vote at the Opus special meeting or any adjournment or postponement of the special meeting. Holders of Opus preferred stock will not be entitled to vote on the compensation proposal or the Opus adjournment proposal.

        The Opus board of directors has unanimously approved the merger agreement and the transactions contemplated therein. Based on Opus's reasons for the merger described in the attached joint proxy statement/prospectus, the Opus board has determined that the merger, the merger agreement and the transactions contemplated by the merger agreement are in the best interests of Opus and its shareholders, and unanimously has recommended that shareholders vote "FOR" approval of the merger proposal, "FOR" approval of the compensation proposal and "FOR" approval of the Opus adjournment proposal.

        If you have any questions concerning the merger or would like additional copies of the joint proxy statement/prospectus or need help voting your shares of Opus common stock or Opus preferred stock, please contact Paul W. Taylor, Opus's President and Chief Executive Officer, or Kevin L. Thompson, Opus's Chief Financial Officer, at (949) 250-9800.

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        Your vote is very important.    Whether or not you plan to attend the Opus special meeting, please promptly complete, sign, date and return your proxy card in the enclosed envelope or vote via the Internet or by telephone pursuant to the instructions provided on the enclosed proxy card.

		By Order of the Board of Directors
		Paul W. Taylor President and Chief Executive Officer

Irvine, California                , 2020

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ADDITIONAL INFORMATION

PACIFIC PREMIER BANCORP, INC. SHAREHOLDERS

        The accompanying joint proxy statement/prospectus incorporates important business and financial information about Pacific Premier Bancorp, Inc., or Pacific Premier, from other documents that are not included in or delivered with this joint proxy statement/prospectus. This information is available to you without charge upon your written or oral request. You can obtain the documents incorporated by reference in this document through the Securities and Exchange Commission website at http://www.sec.gov or by requesting them in writing or by telephone at the address or telephone number listed below. Additionally, if you are a Pacific Premier shareholder and have questions about the issuance of shares of Pacific Premier common stock in connection with the merger or the Pacific Premier special meeting, need additional copies of this joint proxy statement/prospectus or need to obtain proxy cards or other information related to the Pacific Premier proxy solicitation, you may contact Steven R. Gardner, Pacific Premier's Chairman, President and Chief Executive Officer, or Ronald J. Nicolas, Jr., Pacific Premier's Senior Executive Vice President and Chief Financial Officer, at the following address:

Pacific Premier Bancorp, Inc.,
17901 Von Karman Ave.
Suite 1200
Irvine, California 92614

or at the following telephone number:

(949) 864-8000

OPUS BANK SHAREHOLDERS

        The accompanying joint proxy statement/prospectus incorporates important business and financial information about Opus Bank, or Opus, from other documents that are not included in or delivered with this joint proxy statement/prospectus. This information is available to you without charge upon your written or oral request. You can obtain the documents incorporated by reference in this document through the Federal Deposit Insurance Corporation website at http://www.fdic.gov or by requesting them in writing or by telephone at the Opus address or Opus telephone number listed below. Additionally, if you are an Opus shareholder and have questions about the merger, the merger agreement, the other matters to be considered at the Opus special meeting or the accompanying joint proxy statement/prospectus, need additional copies of this joint proxy statement/prospectus or need to obtain proxy cards or other information related to the Opus proxy solicitation, you may contact Paul W. Taylor, Opus's President and Chief Executive Officer, or Kevin L. Thompson, Opus's Chief Financial Officer, or Opus's proxy solicitor at the following addresses or telephone numbers listed below:

        If you are an Opus shareholder, please do not send your stock certificates at this time. You will be sent separate instructions regarding the surrender of your stock certificates. You will not be charged for any of the above referenced documents that are incorporated by reference in this document that you request. To obtain timely delivery of these documents, you must request them no later than five (5) business days before the date of the applicable special meeting. This means that holders of Pacific Premier common stock requesting documents must do so by            , in order to receive them before

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the Pacific Premier special meeting, and holders of Opus common stock and Opus preferred stock requesting documents must do so by            , in order to receive them before the Opus special meeting.

        Pacific Premier shareholders and Opus shareholders should only rely on the information contained in this document. We have not authorized anyone to provide Pacific Premier shareholders or Opus shareholders with different information. The document is dated                    , 2020; Pacific Premier shareholders and Opus shareholders should not assume that information contained in this document is accurate as of any date other than that date. Neither the mailing of this document to Opus or Pacific Premier shareholders nor the issuance by Pacific Premier of Pacific Premier common stock in connection with the transactions contemplated by the merger agreement will create any implications to the contrary.

        This document does not constitute an offer to sell, or a solicitation of an offer to buy any securities, or the solicitation of a consent, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction.

        See the section entitled "Where You Can Find More Information" beginning on page                    of the accompanying joint proxy statement/prospectus for further information.

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QUESTIONS AND ANSWERS
ABOUT THE MERGER, THE PACIFIC PREMIER SPECIAL MEETING AND
THE OPUS SPECIAL MEETING

        The following are some questions that you may have regarding the merger, the Pacific Premier special meeting and the Opus special meeting, and brief answers to those questions. Pacific Premier and Opus advise you to read carefully the remainder of this joint proxy statement/prospectus because the information in this section does not provide all of the information that might be important to you with respect to the merger, the Pacific Premier special meeting and the Opus special meeting. Additional important information is also contained in the documents incorporated by reference into this joint proxy statement/prospectus. See "Where You Can Find More Information" beginning on page     .

Q:    What am I being asked to vote on?

A:

Pacific Premier, Pacific Premier Bank and Opus have entered into the merger agreement, pursuant to which, among other things, Pacific Premier would acquire Opus by merger. If the required shareholder and regulatory approvals are obtained and the merger is subsequently completed, Opus will be merged with and into Pacific Premier Bank, the wholly-owned bank subsidiary of Pacific Premier, with Pacific Premier Bank as the surviving institution.

If you are a Pacific Premier shareholder, you are being asked to vote to approve (i) the issuance of shares of Pacific Premier common stock, par value $0.01 per share, or Pacific Premier common stock, in connection with the merger (which we refer to as the share issuance proposal) and (ii) to adjourn the Pacific Premier special meeting to a later date or dates, if necessary, to permit further solicitation of proxies if there are not sufficient votes at the time of the Pacific Premier special meeting to approve the issuance of shares of Pacific Premier common stock in connection with the merger (which we refer to as the Pacific Premier adjournment proposal).

If you are an Opus shareholder, you are being asked to vote to approve (i) the merger agreement (including the Agreement of Merger incorporated therein) and the merger (which we refer to as the merger proposal), (ii) on a non-binding, advisory basis, the compensation that certain named executive officers of Opus may receive that is based on or otherwise relates to the merger (which we refer to as the compensation proposal) and (iii) to adjourn the Opus special meeting to a later date or dates, if necessary, to permit further solicitation of proxies if there are not sufficient votes at the time of the Opus special meeting to approve the merger proposal (which we refer to as the Opus adjournment proposal). As a result of the merger, Opus will cease to exist and each outstanding share of Opus common stock, no par value, which we refer to as Opus common stock, will be converted into, and canceled in exchange for, the right to receive 0.9000 of a share of Pacific Premier common stock, which we refer to as the exchange ratio, and each outstanding share of Opus series A non-cumulative, non-voting preferred stock, no par value, which we refer to as Opus preferred stock, will be converted into, and converted in exchange for, the right to receive that number of shares of Pacific Premier common stock equal to the product of (i) the number of shares of Opus common stock into which each such share of Opus preferred stock is convertible in connection with the merger, and (ii) the exchange ratio, in each case as further described in "The Merger—The Merger Consideration" beginning on page    .

The merger cannot be completed unless the Pacific Premier shareholders approve the share issuance proposal and the Opus shareholders approve the merger proposal. Pacific Premier is soliciting its shareholders to approve the share issuance proposal at the Pacific Premier special meeting, which we refer to as the Pacific Premier shareholder approval. Opus is soliciting its shareholders to approve the merger proposal at the Opus special meeting, which we refer to as the Opus shareholder approval.

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We have included in this joint proxy statement/prospectus important information about the merger, the merger agreement, a copy of which is included as Appendix A to this joint proxy statement/prospectus, the Pacific Premier proxy solicitation and the Opus proxy solicitation. You should read this information carefully and in its entirety.

This document constitutes both a joint proxy statement of Pacific Premier and Opus and a prospectus of Pacific Premier. It is a joint proxy statement because each of the boards of directors of Pacific Premier and Opus is soliciting proxies from their respective shareholders using this document. It is a prospectus because Pacific Premier, in connection with the merger, is offering shares of Pacific Premier common stock in exchange for the outstanding shares of Opus common stock and Opus preferred stock.

Q:    Will Opus shareholders be able to trade the Pacific Premier common stock that they receive in the merger?

A:

Yes. The Pacific Premier common stock to be issued in the merger to Opus shareholders will be listed on the NASDAQ Global Select Market under the symbol "PPBI." Unless you are deemed an "affiliate" of Pacific Premier after the merger is completed, you may sell the shares of Pacific Premier common stock you receive in the merger without restriction.

Q:    What is the vote required to approve each proposal?

A:

Pacific Premier Proposal 1—The Share Issuance Proposal.    Approval of the share issuance proposal requires the affirmative vote of the majority of the votes cast at the Pacific Premier special meeting by the holders of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting. If you fail to submit a proxy or vote in person at the Pacific Premier special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee with respect to the share issuance proposal, it will have no effect on such proposal (assuming a quorum is present).

Pacific Premier Proposal 2—The Pacific Premier Adjournment Proposal.    Approval of the Pacific Premier adjournment proposal requires the affirmative vote of the majority of the votes cast at the Pacific Premier special meeting by the holders of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting. If you fail to submit a proxy or vote in person at the Pacific Premier special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee with respect to the share issuance proposal, it will have no effect on such proposal (assuming a quorum is present).

Opus Proposal 1—The Merger Proposal.    Approval of the merger proposal requires the affirmative vote of the holders of at least a majority of the outstanding shares of Opus common stock entitled to vote at the Opus special meeting and holders of at least a majority of the outstanding shares of Opus preferred stock entitled to vote at the Opus special meeting, in each case voting as separate classes. If you fail to submit a proxy or to vote in person at the Opus special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee (which we refer to as a broker non-vote) with respect to the merger proposal, it will have the same effect as a vote "AGAINST" the merger proposal.

Opus Proposal 2—The Compensation Proposal.    Approval of the compensation proposal requires the affirmative vote of a majority of shares of Opus common stock entitled to vote represented in person or by proxy and voting at the Opus special meeting (assuming a quorum is present). Holders of Opus preferred stock will not be entitled to vote on the compensation proposal. If you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the compensation proposal, it will have no effect on such proposal (assuming a quorum is present). If you mark "ABSTAIN" on your proxy with respect to

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the compensation proposal, it will have the same effect as a vote "AGAINST" the compensation proposal.

The compensation proposal is advisory, and therefore not binding on Opus, the Opus board's compensation committee or the Opus board. Further, the arrangements are contractual in nature and not, by their terms, subject to Opus shareholder approval. Accordingly, regardless of the outcome of the compensation proposal, if the merger is completed, Opus's named executive officers may be or become entitled to receive the compensation that is based on or otherwise relates to the merger in accordance with the terms and conditions applicable to those payments.

Opus Proposal 3—The Opus Adjournment Proposal.    Approval of the Opus adjournment proposal requires the affirmative vote of a majority of shares of Opus common stock entitled to vote represented in person or by proxy and voting at the Opus special meeting . Holders of Opus preferred stock will not be entitled to vote on the Opus adjournment proposal. If you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the Opus adjournment proposal, it will have no effect on such proposal. If you mark "ABSTAIN" on your proxy with respect to the Opus adjournment proposal, it will have the same effect as a vote "AGAINST" the Opus adjournment proposal.

Q:    Why is my vote important?

A:

The merger cannot be completed unless the Pacific Premier shareholders approve the share issuance proposal and the Opus shareholders approve the merger proposal, which are the only applicable Pacific Premier or Opus shareholder proposals necessary to complete the merger. Information about the Pacific Premier special meeting and the Opus special meeting, the merger and other matters to be considered by shareholders of each of Pacific Premier and Opus is contained in this document.

Opus directors who own shares of Opus common stock, certain executive officers and Opus shareholders, who own in the aggregate approximately 19% of the outstanding shares of Opus common stock and approximately 98% of the outstanding shares of Opus preferred stock, have entered into agreements with Pacific Premier, Pacific Premier Bank, and Opus, which we refer to as the Opus shareholder agreements. Subject to the terms of the Opus shareholder agreements, such shareholders have agreed, among other things, to vote (or cause to be voted), in person, or by proxy, or deliver a written consent (or cause a consent to be delivered) covering all shares of Opus common stock and Opus preferred stock (whether acquired before or after the merger) beneficially owned by him, her or it (x) in favor of approval of the merger, the merger agreement and the transactions contemplated thereby; (y) against any action or agreement that, to the knowledge of the shareholder, would result in a breach of any covenant, representation or warranty or any other material obligation or agreement of Opus contained in the merger agreement or of the shareholder contained in the shareholder agreement; and (z) against any alternative acquisition proposal. These shareholders also agreed to certain restrictions on their ability to transfer their shares of Opus common stock and Opus preferred stock or their voting rights of such shares while the shareholder agreement remains in effect. The shareholder agreement is substantially in the form included as Annex A to the merger agreement.

Q:    Why must the Pacific Premier shareholders approve the issuance of shares of Pacific Premier common stock in connection with the merger?

A:

The Pacific Premier shareholders are required to approve the issuance of shares of the Pacific Premier common stock in connection with the merger, which is estimated to equate to approximately            % of Pacific Premier's issued and outstanding shares of common stock, because Pacific Premier is listed on the NASDAQ Global Select Market and is subject to the

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NASDAQ Global Select Market listing rules. Because Pacific Premier will issue in excess of 20% of its outstanding shares of common stock to the Opus shareholders in connection with the merger, under the NASDAQ Global Select Market listing rules, the shareholders of Pacific Premier are required to approve the issuance of shares of Pacific Premier common stock in connection with the merger. The merger cannot be completed unless the Pacific Premier shareholders approve the share issuance proposal.

Q:    What do each of the boards of directors of Pacific Premier and Opus recommend?

A:

The Pacific Premier board of directors, which we refer to as the Pacific Premier board, has determined that the merger is in the best interests of Pacific Premier and its shareholders and unanimously recommends that Pacific Premier shareholders vote "FOR" approval of the share issuance proposal and "FOR" the Pacific Premier adjournment proposal.

See the section entitled "The Merger—Pacific Premier's Reasons for the Merger and Recommendation of the Pacific Premier Board of Directors" beginning on page    for a more detailed discussion of the Pacific Premier board's recommendations and reasons therefor.

The Opus board of directors, which we refer to as the Opus board, has determined that the merger, the merger agreement and the transactions contemplated by the merger agreement are in the best interests of Opus and its shareholders and has unanimously approved the merger agreement, the merger and the other transactions contemplated by the merger agreement and unanimously recommends that Opus shareholders vote "FOR" approval of the merger proposal, "FOR" approval of the compensation proposal and "FOR" approval of the Opus adjournment proposal.

See the section entitled "The Merger—Opus's Reasons for the Merger and Recommendation of the Opus Board of Directors" beginning on page    for a more detailed discussion of the Opus board's recommendations and reasons therefor. In addition, certain of Opus's officers and directors have financial interests in the transactions contemplated by the merger agreement that are different from, or in addition to, the interests of Opus's shareholders. These interests are described in more detail in the section titled "The Merger—Interests of Certain Opus Officers and Directors in the Merger" beginning on page    .

Q:    Will Opus shareholders have dissenters' rights in connection with the merger?

A:

Holders of Opus common stock do not have the right to dissent from the merger and assert dissenters' rights. Holders of Opus preferred stock have the right to dissent from the merger and assert dissenters' rights, provided the requirements of California law governing dissenters' rights are followed. Please read the section entitled "The Merger—Dissenters' Rights for Holders of Opus Preferred Stock" beginning on page    and the sections of Chapter 13 of the California General Corporation Law, which are set forth in Appendix D to this joint proxy statement/prospectus.

Q:    Are there any risks that should be considered in deciding whether to vote for the matters required to be voted on by the respective shareholders of Pacific Premier and Opus?

A:

Yes. Set forth under the heading of "Risk Factors," beginning on page    , are a number of risk factors that each of the shareholders of Pacific Premier and Opus should consider carefully.

Q:    When do Pacific Premier and Opus expect to complete the merger?

A:

The parties expect to complete the merger during the second quarter of 2020. However, there is no assurance when or if the merger will occur. Prior to the consummation of the merger, Opus

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shareholders must approve the merger proposal at the Opus special meeting, Pacific Premier shareholders must approve the share issuance proposal at the Pacific Premier special meeting, and all requisite regulatory approvals must be obtained and other conditions to the consummation of the merger must be satisfied.

Q:    If the merger is completed, when can Opus shareholders expect to receive the merger consideration?

A:

Promptly following the completion of the merger, Pacific Premier will mail to each former Opus shareholder of record written instructions detailing how its shareholders of record can exchange their shares of Opus common stock and Opus preferred stock for shares of Pacific Premier common stock.

Q.    How will my rights as an Opus shareholder differ following the merger?

A.

Upon completion of the merger, holders of Opus common stock and Opus preferred stock will become Pacific Premier shareholders and their rights as shareholders will be governed by Pacific Premier's second amended and restated certificate of incorporation, as amended, and Pacific Premier's amended and restated bylaws, as well as the Delaware General Corporation Law. The rights associated with Opus common stock and Opus preferred stock are different from the rights associated with Pacific Premier common stock. See "Comparison of the Rights of Shareholders" beginning on page    .

Q.    What happens if the merger is not completed?

A.

If the merger is not completed, holders of Opus common stock and Opus preferred stock will not receive any consideration for their shares in connection with the merger. Instead, each of Pacific Premier and Opus will remain an independent company and each of their common stock will continue to be listed and traded on the NASDAQ Global Select Market. In addition, Opus is required to pay a termination fee to Pacific Premier if the merger is terminated under certain circumstances. See "The Merger—Termination Fee" beginning on page     for a complete discussion of the circumstances under which the termination fee will be required to be paid.

Q:    Will the value of the merger consideration change between the date of the joint proxy statement/prospectus and the time the merger is completed?

A:

Yes. Upon consummation of the merger, each outstanding share of Opus common stock and Opus preferred stock will be converted into, and canceled in exchange for, the right to receive a number of shares of Pacific Premier common stock based upon a fixed exchange ratio. As such, the value of the merger consideration that Opus shareholders will receive in the merger will depend on the market price for a share of Pacific Premier common stock at the time the merger is completed. The market price for a share of Pacific Premier common stock when Opus shareholders receive such shares after the merger is completed could be greater than, less than or the same as the market price of shares of Pacific Premier common stock on the date of this joint proxy statement/prospectus.

Q:    What are the U.S. federal income tax consequences of the merger to Opus shareholders?

A:

The merger is intended to qualify as a "reorganization" within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended, which we refer to as the Code, and it is a condition to completion of the merger that Pacific Premier and Opus each receive a legal opinion to that effect. Assuming the merger qualifies as a reorganization, subject to the limitations and more detailed discussion set forth in "The Merger—Material Federal Income Tax Consequences"

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beginning on page    , an Opus shareholder that is a U.S. holder generally will not recognize gain or loss on the exchange of Opus common stock for Pacific Premier common stock in the merger, other than with respect to cash received in lieu of fractional shares of Pacific Premier common stock.

Tax matters are complicated, and the tax consequences of the merger to a particular Opus shareholder will depend in part on such shareholder's individual circumstances. Accordingly, each Opus shareholder is urged to consult his or her own tax advisor for a full understanding of the tax consequences of the merger to such shareholder, including the applicability and effect of federal, state, local and foreign income and other tax laws.

Q:    What do I need to do now?

A:

Read and consider the information contained in this joint proxy statement/prospectus, including the appendices, carefully and then please submit as soon as possible either your Pacific Premier proxy, in the case of Pacific Premier shareholders, or your Opus proxy, in the case of Opus shareholders.

Q.    Should I send in my Opus stock certificates now?

A.

No. Please do not send in your certificates if you hold Opus common stock or Opus preferred stock in certificated form until you receive instructions to do so. You are not required to take any special additional actions if your shares of Opus common stock or Opus preferred stock are held in book-entry form. After the completion of the merger, an exchange agent will send you instructions for exchanging your shares.

If you hold your shares of Opus common stock or Opus preferred stock in certificated form, and do not know where your stock certificates are located, you may want to find them now so you do not experience delays receiving your merger consideration. If you are unable to locate your original stock certificate(s), you should contact the exchange agent, American Stock Transfer and Trust Company, at (800) 937-5449. See "The Merger—Procedures for Exchanging Opus Common Stock and Opus Preferred Stock Certificates" beginning on page    .

Q.    What do I do if I receive more than one joint proxy statement/prospectus or set of voting instructions?

A.

Pacific Premier shareholders and Opus shareholders may receive more than one set of voting materials, including multiple copies of this joint proxy statement/prospectus and multiple proxy cards or voting instruction cards. For example, if you hold shares of Pacific Premier common stock, Opus common stock or Opus preferred stock in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold such shares. If you are a holder of record of Pacific Premier common stock, Opus common stock or Opus preferred stock and your shares are registered in more than one name, you will receive more than one proxy card. In addition, if you are a holder of both Pacific Premier common stock and Opus common stock or Opus preferred stock, you will receive one or more separate proxy cards or voting instruction cards for each company. Please complete, sign, date and return each proxy card and voting instruction card that you receive or otherwise follow the voting instructions set forth in this joint proxy statement/prospectus to ensure that you vote every share of Pacific Premier common stock, Opus common stock and/or Opus preferred stock that you own.

Q:    Whom should I call if I have questions?

A:

If you are an Opus shareholder and have any questions concerning the merger or joint proxy statement/prospectus, would like additional copies of the joint proxy statement/prospectus or need

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help voting your shares of Opus common stock or Opus preferred stock, please contact Paul W. Taylor, President and Chief Executive Officer, at (949) 250-9800, or Kevin L. Thompson, Chief Financial Officer, at (949) 250-9800 or Opus's proxy solicitor at (866) 828-6934 or opb@dfking.com.

If you are a Pacific Premier shareholder and have any questions concerning the merger or joint proxy statement/prospectus, would like additional copies of the joint proxy statement/prospectus or need help voting your shares of Pacific Premier common stock, please contact Steven R. Gardner, Pacific Premier's Chairman, President and Chief Executive Officer, at (949) 864-8000, or Ronald J. Nicolas, Jr., Pacific Premier's Senior Executive Vice President and Chief Financial Officer, at (949) 864-8000.

MATTERS PERTAINING TO THE PACIFIC PREMIER SPECIAL MEETING

Q:    When and where is the Pacific Premier special meeting?

A:

The Pacific Premier special meeting will be held at                 a.m., Pacific Time, on                at 17901 Von Karman Avenue, Suite 200, Irvine, California 92614.

Q:    Who is entitled to vote at the Pacific Premier special meeting?

A:

The holders of record of Pacific Premier common stock at the close of business on    , 2020, which is the date Pacific Premier's board of directors has fixed as the record date for the Pacific Premier special meeting, which we refer to as the Pacific Premier record date, are entitled to vote at the Pacific Premier special meeting.

Q:    How many votes do shareholders of Pacific Premier have?

A:

Pacific Premier shareholders are entitled to one vote in the Pacific Premier proxy solicitation for each share of Pacific Premier common stock held as of the Pacific Premier record date. As of the close of business on the Pacific Premier record date, there were    outstanding shares of Pacific Premier common stock.

Q:    What constitutes a quorum for the Pacific Premier special meeting?

A:

A quorum, consisting of the holders of a majority of the shares of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting, must be present in person or by proxy before any action may be taken at the Pacific Premier special meeting. Once a share of Pacific Premier common stock is represented at the Pacific Premier special meeting, it will be counted for the purpose of determining a quorum not only at the Pacific Premier special meeting but also at any adjournment or postponement of the Pacific Premier special meeting. In the event that a quorum is not present at the Pacific Premier special meeting, it is expected that the Pacific Premier special meeting will be adjourned or postponed.

Q:    What is the vote required to approve each proposal at the Pacific Premier special meeting?

A:

Pacific Premier Proposal 1—The Share Issuance Proposal.    Approval of the share issuance proposal requires the affirmative vote of the majority of the votes cast at the Pacific Premier special meeting by the holders of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting. If you fail to submit a proxy or vote in person at the Pacific Premier special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee with respect to the share issuance proposal, it will have no effect on such proposal (assuming a quorum is present).

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Pacific Premier Proposal 2—The Pacific Premier Adjournment Proposal.    Approval of the Pacific Premier adjournment proposal requires the affirmative vote of the majority of the votes cast at the Pacific Premier special meeting by the holders of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting. If you fail to submit a proxy or vote in person at the Pacific Premier special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee with respect to the share issuance proposal, it will have no effect on such proposal (assuming a quorum is present).

Q:    If my shares of Pacific Premier common stock are held in street name by my broker, will my broker automatically vote my shares for me?

A:

No. Your bank, broker or other nominee will not be able to vote shares held by it in street name on your behalf without instructions from you. You should instruct your bank, broker or other nominee to vote your shares by following the directions your bank, broker or other nominee provides to you.

Q:    What if I abstain from voting, fail to vote or fail to instruct my bank, broker or other nominee?

A:

The approval of the share issuance proposal and the Pacific Premier adjournment proposal requires the affirmative vote of the majority of the votes cast at the Pacific Premier special meeting by the holders of Pacific Premier common stock entitled to vote at the Pacific Premier special meeting. As such, abstentions and broker non-votes of Pacific Premier common stock and failures to vote shares of Pacific Premier common stock by failing to return a properly executed proxy and failing to appear in person at the Pacific Premier special meeting, will not have any effect on the approval of the share issuance proposal or the Pacific Premier adjournment proposal.

Q:    Can I attend the Pacific Premier special meeting and vote my shares in person?

A:

Yes. While not required to, all Pacific Premier shareholders are invited to attend the Pacific Premier special meeting. Shareholders of record can vote in person at the Pacific Premier special meeting. If your shares are held in street name, then you are not the shareholder of record and you must bring a legal proxy from your broker, bank or other nominee confirming that you are the beneficial owner of the shares in order to vote in person at the applicable special meeting.

Q:    Can I change my vote?

A:

Yes. Regardless of the method used to cast a vote, you may change your vote at any time before your proxy is voted at the Pacific Premier special meeting. You may do so in one of the following ways:

•

by delivering to Pacific Premier prior to the Pacific Premier special meeting, a written notice of revocation addressed to Ronald Nicolas, Senior Executive Vice President and Chief Financial Officer, Pacific Premier Bancorp, Inc., 17901 Von Karman Ave., Suite 1200, Irvine, California 92614;

•

completing, signing and returning a new proxy card with a later date before the date of the Pacific Premier special meeting, and any earlier proxy will be revoked automatically;

•

calling the toll free number listed on the Pacific Premier proxy card or by accessing the Internet site listed on the Pacific Premier proxy card to change your vote before 11:59 p.m., Eastern Time, on                , 2020, in which case the later submitted proxy via telephone or Internet, as the case may be, will be recorded and the earlier dated proxy will be revoked; or

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•

attending the Pacific Premier special meeting and voting in person, and any earlier proxy will be revoked. However, simply attending the Pacific Premier special meeting without voting will not revoke an earlier proxy voted by such person.

If you have instructed a bank, broker or other nominee to vote your shares of Pacific Premier common stock, you must follow directions received from the bank, broker or other nominee to change such vote.

Q:    What if I am a record holder and I do not indicate a decision with respect to the matters required to be voted on by the shareholders of Pacific Premier?

A:

If you are a Pacific Premier record holder and you returned a signed proxy card without indicating your decision on the proposal to approve the share issuance proposal , you will have given your vote to issue Pacific Premier common stock in connection with the merger.

MATTERS PERTAINING TO THE OPUS SPECIAL MEETING

Q:    When and where is the Opus special meeting?

A:

The Opus special meeting will be held at 9:00 a.m., Pacific Time, on                at the Pacific Club, 4110 MacArthur Blvd, Newport Beach, California 92660.

Q:    Who is entitled to vote at the Opus special meeting?

A:

The holders of record of Opus common stock and holders of record of Opus preferred stock at the close of business on                , 2020, which is the date Opus's board of directors has fixed as the record date for the Opus special meeting, which we refer to as the Opus record date, are entitled to vote at the Opus special meeting.

Q:    How many votes do shareholders of Opus have?

A:

Opus shareholders are entitled to one vote in the Opus proxy solicitation for each share of Opus common stock and one vote for each share of Opus preferred stock held as of the Opus record date. As of the closing of business on the Opus record date, there were            outstanding shares of Opus common stock and            outstanding shares of Opus preferred stock.

Q:    What constitutes a quorum for the Opus special meeting?

A:

A quorum, consisting of the holders of a majority of the shares entitled to vote at the Opus special meeting, must be present in person or represented by proxy before any action may be taken at the Opus special meeting. Once a share of Opus common stock or Opus preferred stock is represented at the Opus special meeting, it will be counted for the purpose of determining a quorum not only at the Opus special meeting but also, in the case of a share of Opus common stock, at any adjournment or postponement of the Opus special meeting. In the event that a quorum is not present at the Opus special meeting, it is expected that the Opus special meeting will be adjourned or postponed. Abstentions of Opus common stock or Opus preferred stock will be treated as represented and present for quorum purposes. Broker non-votes of Opus common stock and Opus preferred stock and the failure to vote shares of either Opus common stock or Opus preferred stock by failing to return a properly executed proxy and failing to appear in person at the Opus special meeting, which is referred to as a failure to vote, will not be counted as present for purposes of establishing a quorum at the Opus special meeting and will not be voted on any of the proposals at the Opus special meeting.

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Q:    What is the vote required to approve each proposal at the Opus special meeting?

A:

Opus Proposal 1—The Merger Proposal.    Approval of the merger proposal requires the affirmative vote of the holders of at least a majority of the outstanding shares of Opus common stock entitled to vote at the Opus special meeting and holders of at least a majority of the outstanding shares of Opus preferred stock entitled to vote at the Opus special meeting, in each case voting as separate classes. If you fail to submit a proxy or to vote in person at the Opus special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee (which we refer to as a broker non-vote) with respect to the merger proposal, it will have the same effect as a vote "AGAINST" the merger proposal.

Opus Proposal 2—The Compensation Proposal.    Approval of the compensation proposal requires the affirmative vote of a majority of shares of Opus common stock entitled to vote represented in person or by proxy and voting at the Opus special meeting (assuming a quorum is present). Holders of Opus preferred stock will not be entitled to vote on the compensation proposal. If you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the compensation proposal, it will have no effect on such proposal (assuming a quorum is present). If you mark "ABSTAIN" on your proxy with respect to the compensation proposal, it will have the same effect as a vote "AGAINST" the compensation proposal.

The compensation proposal is advisory, and therefore not binding on Opus, the Opus board's compensation committee or the Opus board. Further, the arrangements are contractual in nature and not, by their terms, subject to Opus shareholder approval. Accordingly, regardless of the outcome of the compensation proposal, if the merger is completed, Opus's named executive officers may be or become entitled to receive the compensation that is based on or otherwise relates to the merger in accordance with the terms and conditions applicable to those payments.

Opus Proposal 3—The Opus Adjournment Proposal.    Approval of the Opus adjournment proposal requires the affirmative vote of a majority of shares of Opus common stock entitled to vote represented in person or by proxy and voting at the Opus special meeting . Holders of Opus preferred stock will not be entitled to vote on the Opus adjournment proposal. If you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the Opus adjournment proposal, it will have no effect on such proposal. If you mark "ABSTAIN" on your proxy with respect to the Opus adjournment proposal, it will have the same effect as a vote "AGAINST" the Opus adjournment proposal.

Q:    If my shares of Opus common stock or Opus preferred stock are held in street name by my broker, will my broker automatically vote my shares for me?

A:

No. Your bank, broker or other nominee will not be able to vote shares held by it in street name on your behalf without instructions from you. You should instruct your bank, broker or other nominee to vote your shares by following the directions your bank, broker or other nominee provides to you.

Q:    What if I abstain from voting, fail to vote or fail to instruct my bank, broker or other nominee?

A:

A broker non-vote occurs when a bank, broker, trustee or other nominee is not permitted to vote on a "non-routine" matter without instructions from the beneficial owner of the shares and the beneficial owner fails to provide the bank, broker, trustee or other nominee with such instructions. Broker non-votes only count toward a quorum if at least one proposal is presented with respect to which the bank, broker, trustee or other nominee has discretionary authority. It is expected that all proposals to be voted on at the Opus special meeting will be "non-routine" matters, and, as such, broker non-votes, if any, will not be counted as present and entitled to vote for purposes of

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determining a quorum at the Opus special meeting. If your bank, broker, trustee or other nominee holds your shares of Opus common stock or Opus preferred stock in "street name," such entity will vote your shares of Opus common stock or Opus preferred stock only if you provide instructions on how to vote by complying with the voter instruction form sent to you by your bank, broker, trustee or other nominee with this joint proxy statement/prospectus.

With respect to the merger proposal, if you fail to submit a proxy or vote in person at the Opus special meeting, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other nominee with respect to the merger proposal, it will have the same effect as a vote "AGAINST" the merger proposal.

With respect to the compensation proposal, if you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the compensation proposal, it will have no effect on such proposal (assuming a quorum is present). If you mark "ABSTAIN" on your proxy with respect to the compensation proposal, it will have the same effect as a vote "AGAINST" the compensation proposal.

With respect to the Opus adjournment proposal, if you fail to submit a proxy or vote in person at the Opus special meeting, or fail to instruct your bank, broker or other nominee with respect to the Opus adjournment proposal, it will have no effect on such proposal. If you mark "ABSTAIN" on your proxy with respect to the Opus adjournment proposal, it will have the same effect as a vote "AGAINST" the Opus adjournment proposal.

Holders of Opus preferred stock will not be entitled to vote on the compensation proposal or the Opus adjournment proposal. Abstentions will be considered for purposes of determining whether a quorum is present at the Opus special meeting. However, abstentions are not counted as affirmative votes in favor of the merger proposal, compensation proposal or Opus adjournment proposal.

Q:    Can I attend the Opus special meeting and vote my shares in person?

A:

Yes. While not required to, all Opus shareholders are invited to attend the Opus special meeting. Shareholders of record can vote in person at the Opus special meeting. If your shares are held in street name, then you are not the shareholder of record and you must bring a legal proxy from your broker, bank or other nominee confirming that you are the beneficial owner of the shares in order to vote in person at the applicable special meeting.

Q:    Can I change my vote?

A:

Yes. Regardless of the method used to cast a vote, you may change your vote at any time before your proxy is voted at the Opus special meeting. You may do so in one of the following ways:

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by delivering to Opus prior to the Opus special meeting, a written notice of revocation addressed to Kevin L. Thompson, Chief Financial Officer, Opus Bank, 19900 MacArthur Boulevard, 12^th Floor, Irvine, California 92612;

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completing, signing and returning a new proxy card with a later date before the date of the Opus special meeting, and any earlier proxy will be revoked automatically;

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calling the toll free number listed on the Opus proxy card or by accessing the Internet site listed on the Opus proxy card to change your vote before 11:59 p.m., Eastern Time, on                , 2020, in which case the later submitted proxy via telephone or Internet, as the case may be, will be recorded and the earlier dated proxy will be revoked; or

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attending the Opus special meeting and voting in person, and any earlier proxy will be revoked. However, simply attending the Opus special meeting without voting will not revoke an earlier proxy voted by such person.

If you have instructed a bank, broker or other nominee to vote your shares of Opus common stock or Opus preferred stock, you must follow directions received from the bank, broker or other nominee to change such vote.

Q:    What if I am a record holder and I do not indicate a decision with respect to the matters required to be voted on by the Opus shareholders?

A:

If you are an Opus record holder and you return a signed proxy card without indicating your decision on the merger proposal, compensation proposal and the Opus adjournment proposal, you will have given your consent to vote in favor of the merger proposal, the compensation proposal and the Opus adjournment proposal.

Q:    Whom may I contact if I cannot locate my Opus common stock or Opus preferred stock certificate(s)?

A:

If you cannot locate your certificates representing shares of Opus common stock or Opus preferred stock and believe them to be lost, stolen or destroyed, please follow the instructions in the letter of transmittal you will receive from the exchange agent dealing with lost, stolen, or destroyed certificates. You will then be provided with an affidavit or lost stock certificates to complete and return to the exchange agent.

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